There are several existing systems that provide a camera position and orientation information. Free-D camera tracking system is developed by the British Broadcasting Co. BBC research and development R&D. It uses a number of markers placed out-of-shot, for example on the ceiling of a studio, that are viewed by a small auxiliary camera mounted on the side of each normal camera. The markers are composed of a number of concentric white and black rings forming a type of barcode, each marker has a unique code number. A serial digital video signal from the auxiliary camera is analyzed by a purpose-built hardware unit to calculate the precise position and orientation of the camera in real time.
Bluei puts out a product line that uses another technique that can acquire position information. It is a high-resolution camera-based tracking system that can be mounted to any movable device, for example a studio dolly, and reads a floor covering that is digitally encoded with a specially designed pattern. The floor pattern has been designed and tested to be bluescreen compatible, thereby allowing the system to be used unobtrusively within virtual reality studios.
Although the Global Positioning System GPS can also be used to globally locate the position of the camera, it would not be accurate enough for the requirements of a virtual studio. Products providing orientation information are available from Vinten and Radamec. Also FreeD provides the orientation of the camera, too.
The current location and orientation techniques are expensive, require tedious and daily system calibration. They cannot be easily extended to support other applications that are not possible with Free-D. For instance, the same framework cannot be used to acquire other information such as temperature, humidity, or vibration. Accordingly, there is a need for a camera location and orientation systems that overcomes the cost and operating disadvantages of existing systems.